The claimed invention relates to a coupling having a first member that is rotatable relative to a second member and to a method of assembling a coupling.
Hoses are used for the transfer of high-pressure fluids in hand held spray guns and wands. Such spray guns and wands are used in pressure washers and airless paint sprayers, among other devices. Hoses are typically stiff and can be relatively difficult to manage when under pressure from the fluid being sprayed. Swivel couplings make the use of such hoses more manageable by allowing the spray gun or wand to rotate relative to the hose.
Ball bearings have been used in swivel couplings to transmit the load between the connected sections. Known devices are complicated in design and often include cross-drilled loading holes through which the ball bearings are loaded into a bearing race. Once the ball bearings are loaded into the race, the loading holes are plugged with hole plugs or other material in order to retain the balls in the race.
The claimed invention concerns a swivel coupling comprising a male member, a female member, a locking member, and a plurality of ball bearings. The male member has an outer surface and a bore extending axially therethrough. An annular groove is formed on the outer surface of the male member. The female member has a bore extending axially therethrough and is configured to connect concentrically and rotatably with the male member. The female member overlaps the male member to form a common central flow passageway. An annular groove is defined at one end of the female member and is positioned adjacent the annular groove of the male member. The locking member is movably mounted around the male and female members and comprises an annular groove that is positioned adjacent the annular grooves of the female and male members. The grooves together defining an annular ball race. The ball bearings are trapped in the ball race and abutted by the annular grooves of the female, male, and locking members. The ball bearings are rotatable in the ball race and the female member is axially rotatable relative to the male member around the ball bearings.
In another embodiment of the invention, the swivel coupling comprises a male, female, and locking member, as discussed above. A plurality of ball bearings are trapped in the ball race. The ball bearings are rotatable in the ball race and the female member is axially rotatable relative to the male member around the ball bearings. A force applied to the male member is transmitted through the ball bearings to the locking member. The force has a force vector that diverges from an axis of the male member at an acute angle through the ball bearings and into the locking member.
In yet another embodiment, a method of assembling the swivel coupling includes positioning the male member so that a longitudinal axis of the male member is vertical and positioning the locking member around the male member such that the annular groove of the locking member is positioned in the vicinity of the annular groove of the male member. An annular channel is defined between the locking member and the male member and the annular channel has a cross-section larger than the diameter of the ball bearings. The method also includes dropping the plurality of ball bearings into the annular channel and inserting the female member into the annular channel such that the annular groove of the female member is positioned adjacent the male member annular groove. The method further includes moving the locking member over an outer surface of the female member until the locking member is locked to the female member. The annular grooves of the female, male, and locking members trap the plurality of ball bearings in the ball race.